Release v174 (#1023 )

Correctly handle failed pip/setuptools/wheel installs (#1007 )
They are now displayed in the build output (instead of being sent to `/dev/null`) and fail the build early instead of failing later in `bin/steps/pip-install`. Fixes #1002.
2026-06-05 23:10:16 +00:00 · 2020-07-30 09:15:44 +01:00 · 2020-07-29 19:11:35 +01:00 · 2020-07-29 19:11:35 +01:00 · 2020-07-29 19:11:35 +01:00 · 2020-07-29 19:11:35 +01:00
135 changed files with 1532 additions and 23663 deletions
@@ -1 +1 @@
-* @heroku/languages
+* @heroku/languages
@@ -0,0 +1,17 @@
 name: Check Changelog
 on:
  pull_request:
    types: [opened, reopened, edited, synchronize]
 jobs:
  check:
    runs-on: ubuntu-latest
    if: |
      !contains(github.event.pull_request.body, '[skip changelog]') &&
      !contains(github.event.pull_request.body, '[changelog skip]') &&
      !contains(github.event.pull_request.body, '[skip ci]')
    steps:
      - uses: actions/checkout@v1
      - name: Check that CHANGELOG is touched
        run: git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md
@@ -7,3 +7,8 @@ repos/*
 #Venv
 buildpack/*
 builds/dockerenv.staging*
 builds/dockerenv.production
 test/scratch
@@ -1,5 +1,7 @@
 repos:
-   repo: git://github.com/detailyang/pre-commit-shell
+-   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: 1.0.4
+    rev: v2.3.0
    hooks:
-    - id: shell-lint
+    -   id: check-yaml
    -   id: end-of-file-fixer
    -   id: trailing-whitespace
@@ -1,35 +1,44 @@
-language: ruby
+language: minimal
-dist: trusty
+dist: bionic
-sudo: required
+branches:
-rvm:
+  only:
- 2.4.4
+  - master
-before_script:
+
-  - gem install bundler -v 1.16.2
+script:
-  - bundle exec hatchet ci:setup
+  - make test STACK="${STACK}" TEST_CMD="${TEST_CMD}"
 jobs:
  include:
-  - stage: Bash linting (shellcheck)
+  - name: Bash linting (shellcheck)
    sudo: false
    script: make check
-  - stage: Stack Unit Tests
+  - name: Hatchet integration tests
-    services: docker
+    if: env(TRAVIS_PULL_REQUEST_SLUG) = env(TRAVIS_REPO_SLUG)
-    env: STACK=heroku-18
+    language: ruby
-    script: "./tests.sh"
+    rvm:
-  - stage: Stack Unit Tests
+      - 2.6.6
-    services: docker
+    before_script:
-    env: STACK=heroku-16
+      - gem install bundler -v 1.16.2
-    script: "./tests.sh"
+    script:
-  - stage: Stack Unit Tests
+      - bundle exec hatchet ci:setup
-    services: docker
+      - PARALLEL_SPLIT_TEST_PROCESSES=11 bundle exec parallel_split_test spec/hatchet/
-    env: STACK=cedar-14
+
    script: "./tests.sh"
  - stage: Hatchet Integration
    script: "bundle exec rspec"
 env:
  jobs:
    - STACK=cedar-14 TEST_CMD=test/run-deps
    - STACK=cedar-14 TEST_CMD=test/run-versions
    - STACK=cedar-14 TEST_CMD=test/run-features
    - STACK=heroku-16 TEST_CMD=test/run-deps
    - STACK=heroku-16 TEST_CMD=test/run-versions
    - STACK=heroku-16 TEST_CMD=test/run-features
    - STACK=heroku-18 TEST_CMD=test/run-deps
    - STACK=heroku-18 TEST_CMD=test/run-versions
    - STACK=heroku-18 TEST_CMD=test/run-features
  global:
-  - HATCHET_RETRIES=3
+    - HATCHET_RETRIES=3
-  - IS_RUNNING_ON_CI=true
+    - IS_RUNNING_ON_CI=true
-  - HATCHET_APP_LIMIT=5
+    - HATCHET_APP_LIMIT=80
-  - HATCHET_DEPLOY_STRATEGY=git
+    - HATCHET_DEPLOY_STRATEGY=git
-  - secure: yjtlPE5FbVxTKnjUy/tZUBgSEf4qADD3QOxtgziuid73S0U/1IEXlMGFULsQzIjtlHKmHeywZqpVVEpthIH4RuT7uoX1Pb7SSM/g0T8fT3VoEFbFK1uYl0oZQbUS4Klxv9tPiumj8if3m6ULEGIz1X0wZcMOC0tMLwVCnwmap0E=
+    - secure: yjtlPE5FbVxTKnjUy/tZUBgSEf4qADD3QOxtgziuid73S0U/1IEXlMGFULsQzIjtlHKmHeywZqpVVEpthIH4RuT7uoX1Pb7SSM/g0T8fT3VoEFbFK1uYl0oZQbUS4Klxv9tPiumj8if3m6ULEGIz1X0wZcMOC0tMLwVCnwmap0E=
-  - secure: ZeFTHWwnpIKE9nAqs88ocmiQh7bKce84lilGm5J23nf3N6V4wNyLwqlkvsM008WGBCaOg9AUx7ZunasT0ANsR5gLP3eV2UUg7ILdRgV2Gy13eNRFheC4PHdN92RqQ3aKoqlIv2K999xlhVjod0NzhkQQXB6PddfQINbuU7ks6As=
+    - secure: ZeFTHWwnpIKE9nAqs88ocmiQh7bKce84lilGm5J23nf3N6V4wNyLwqlkvsM008WGBCaOg9AUx7ZunasT0ANsR5gLP3eV2UUg7ILdRgV2Gy13eNRFheC4PHdN92RqQ3aKoqlIv2K999xlhVjod0NzhkQQXB6PddfQINbuU7ks6As=
@@ -1,5 +1,129 @@
 # Python Buildpack Changelog
 # Master
 # 174 (2020-07-30)
 - For repeat builds, also manage the installed versions of setuptools/wheel, rather than just that of pip (#1007).
 - Install an explicit version of wheel rather than the latest release at the time (#1007).
 - Output the installed version of pip, setuptools and wheel in the build log (#1007).
 - Errors installing pip/setuptools/wheel are now displayed in the build output and fail the build early (#1007).
 - Install pip using itself rather than `get-pip.py` (#1007).
 - Disable pip's version check + cache when installing pip/setuptools/wheel (#1007).
 - Install setuptools from PyPI rather than a vendored copy (#1007).
 - Reduce the number of environment variables exposed to `bin/{pre,post}_compile` and other subprocesses (#1011)
 # 173 (2020-07-21)
 - Python 3.8.5 is now available (CPython)
 # 172 (2020-07-17)
 - Python 3.8.4 is now available (CPython)
 # 171 (2020-07-07)
 - Python 3.6.11 and 3.7.8 are now available (CPython).
 # 170 (2020-05-19)
 - Python 2.7.18, 3.5.9, 3.7.7 and 3.8.3 are now available (CPython).
 - PyPy 2.7 and 3.6, version 7.3.1 are now available (Note: PyPy support is in beta)
 - Docs: Fix explanation of runtime.txt generation when using pipenv
 - Bugfix: Correctly detect Python version when using a `python_version` of `3.8` in `Pipfile.lock`
 --------------------------------------------------------------------------------
 # 169 (2020-04-22)
 - Add a Hatchet test for python 3.8.2
 - Set Code Owners to @heroku/langauges
 - Bugfix: Caching on subsequent redeploys
 - Update tests to support latest version of Python
 # 168 (2020-04-06)
 - Doc: Update Readme with version numbers
 - update Code Owners to include the Heroku Buildpack Maintainers team
 - Deprecation warning: BUILD_WITH_GEO_LIBRARIES is now deprecated. See warning for details.
 - Clean up build log output
 - Update Python versions in README to match docs
 - Django version detection fixed, link updated
 # 167 (2020-03-26)
 - Add failcase for cache busting
 - Bugfix: Clearing pip dependencies
 # 166 (2020-03-05)
 - Correct ftp to https in vendored file
 - Warn for Django 1.11 approaching EOL, provide link to roadmap
 # 165 (2020-02-27)
 - Python 3.8.2 now available.
 # 164 (2020-02-20)
 - Update requirements.txt builds to use Pip 20.0.2
 - Download get-pip.py to tmpdir instead of root dir
 # 163 (2019-12-23)
 - New pythons released:
  Python 3.8.1, 3.7.6, 3.6.10 (CPython)
  Beta Release: Pypy 2.7 and 3.6, version 7.2.0
 # 162 (2019-12-06)
 - Bug fix: fragile sqlite3 install
 # 161 (2019-12-2)
 - Bug fix: Sqlite3 version bump
 # 160 (2019-10-23)
 - Bugfix: Pipenv no longer installs twice in CI
 # 159 (2019-10-22)
 - Python 2.7.17 now available on Heroku 18 and 16.
 # 158 (2019-10-21)
 - Python 3.7.5 and 3.8.0 now available on Heroku 18 and 16.
 - Add support for Python 3.8 branch
 - Sqlite3 Update:
  - Test Improvements
 - Add support for staging binary testing
 # 157 (2019-09-18)
 - Typo fixes
 # 156 (2019-09-12)
 - Python 3.6.9 and 3.7.4 now available.
 - Move get-pip utility to S3
 - Build utility and documentation updates
 - Bump Hatchet tests to point at new default python version.
 # 155 (2019-08-22)
 add docs and make target for heroku-18 bob builds
 # 154 (2019-07-17)
 Fix python 3.5.7 formula actually building 3.7.2
 # 153 (2019-06-21)
 Hotfix for broken heroku-16 deploys
 # 152 (2019-04-04)
 Python 3.7.3 now available.
@@ -1,13 +0,0 @@
 FROM heroku/heroku:18-build
 WORKDIR /app
 ENV WORKSPACE_DIR="/app/builds" \
    S3_BUCKET="lang-python" \
    S3_PREFIX="heroku-18/"
 RUN apt-get update && apt-get install -y python-pip && rm -rf /var/lib/apt/lists/*
 COPY requirements.txt /app/
 RUN pip install --disable-pip-version-check --no-cache-dir -r /app/requirements.txt
 COPY . /app
@@ -4,3 +4,5 @@ gem "rspec"
 gem "heroku_hatchet"
 gem "rspec-retry"
 gem "rake"
 gem "parallel_split_test"
@@ -1,21 +1,22 @@
 GEM
  remote: https://rubygems.org/
  specs:
-    activesupport (5.2.1)
+    activesupport (6.0.3.1)
      concurrent-ruby (~> 1.0, >= 1.0.2)
      i18n (>= 0.7, < 2)
      minitest (~> 5.1)
      tzinfo (~> 1.1)
-    concurrent-ruby (1.1.3)
+      zeitwerk (~> 2.2, >= 2.2.2)
    concurrent-ruby (1.1.6)
    diff-lcs (1.3)
    erubis (2.7.0)
-    excon (0.62.0)
+    excon (0.73.0)
    heroics (0.0.25)
      erubis (~> 2.0)
      excon
      moneta
      multi_json (>= 1.9.2)
-    heroku_hatchet (4.0.6)
+    heroku_hatchet (5.0.3)
      excon (~> 0)
      minitest-retry (~> 0.1.9)
      platform-api (~> 2)
@@ -23,17 +24,21 @@ GEM
      rrrretry (~> 1)
      thor (~> 0)
      threaded (~> 0)
-    i18n (1.1.1)
+    i18n (1.8.2)
      concurrent-ruby (~> 1.0)
-    minitest (5.11.3)
+    minitest (5.14.1)
    minitest-retry (0.1.9)
      minitest (>= 5.0)
    moneta (1.0.0)
-    multi_json (1.13.1)
+    multi_json (1.14.1)
    parallel (1.19.1)
    parallel_split_test (0.7.0)
      parallel (>= 0.5.13)
      rspec (>= 3.1.0)
    platform-api (2.2.0)
      heroics (~> 0.0.25)
      moneta (~> 1.0.0)
-    rake (12.3.1)
+    rake (12.3.3)
    repl_runner (0.0.3)
      activesupport
    rrrretry (1.0.0)
@@ -55,17 +60,19 @@ GEM
    thor (0.20.3)
    thread_safe (0.3.6)
    threaded (0.0.4)
-    tzinfo (1.2.5)
+    tzinfo (1.2.7)
      thread_safe (~> 0.1)
    zeitwerk (2.3.0)
 PLATFORMS
  ruby
 DEPENDENCIES
  heroku_hatchet
  parallel_split_test
  rake
  rspec
  rspec-retry
 BUNDLED WITH
-   1.16.3
+   2.1.4
@@ -1,32 +1,32 @@
 # These targets are not files
-.PHONY: tests
+.PHONY: check test buildenv-heroku-16 buildenv-heroku-18 tools
-test: test-heroku-18 test-heroku-16
+STACK ?= heroku-18
 TEST_CMD ?= test/run-versions && test/run-features && test/run-deps
 ifeq ($(STACK),cedar-14)
 	# Cedar-14 doesn't have a build image varient.
 	IMAGE_TAG := heroku/cedar:14
 else
 	# Converts a stack name of `heroku-NN` to its build Docker image tag of `heroku/heroku:NN-build`.
 	IMAGE_TAG := heroku/$(subst -,:,$(STACK))-build
 endif
 check:
 	@shellcheck -x bin/compile bin/detect bin/release bin/test-compile bin/utils bin/warnings bin/default_pythons
 	@shellcheck -x bin/steps/collectstatic bin/steps/eggpath-fix  bin/steps/eggpath-fix2 bin/steps/gdal bin/steps/geo-libs bin/steps/mercurial bin/steps/nltk bin/steps/pip-install bin/steps/pip-uninstall bin/steps/pipenv bin/steps/pipenv-python-version bin/steps/pylibmc bin/steps/python
 	@shellcheck -x bin/steps/hooks/*
-test-cedar-14:
+test:
-	@echo "Running tests in docker (cedar-14)..."
+	@echo "Running tests using: STACK=$(STACK) TEST_CMD='$(TEST_CMD)'"
 	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=cedar-14" heroku/cedar:14 bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
 	@echo ""
-
+	@docker run --rm -it -v $(PWD):/buildpack:ro -e "STACK=$(STACK)" "$(IMAGE_TAG)" bash -c 'cp -r /buildpack /buildpack_test && cd /buildpack_test && $(TEST_CMD)'
 test-heroku-16:
 	@echo "Running tests in docker (heroku-16)..."
 	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-16" heroku/heroku:16-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
 	@echo ""
 test-heroku-18:
 	@echo "Running tests in docker (heroku-18)..."
 	@docker run -v $(shell pwd):/buildpack:ro --rm -it -e "STACK=heroku-18" heroku/heroku:18-build bash -c 'cp -r /buildpack /buildpack_test; cd /buildpack_test/; test/run;'
 	@echo ""
 buildenv-heroku-16:
 	@echo "Creating build environment (heroku-16)..."
 	@echo
-	@docker build --pull -t python-buildenv-heroku-16 .
+	@docker build --pull -f $(shell pwd)/builds/heroku-16.Dockerfile -t python-buildenv-heroku-16 .
 	@echo
 	@echo "Usage..."
 	@echo
@@ -36,6 +36,19 @@ buildenv-heroku-16:
 	@echo
 	@docker run -it --rm python-buildenv-heroku-16
 buildenv-heroku-18:
 	@echo "Creating build environment (heroku-18)..."
 	@echo
 	@docker build --pull -f $(shell pwd)/builds/heroku-18.Dockerfile -t python-buildenv-heroku-18 .
 	@echo
 	@echo "Usage..."
 	@echo
 	@echo "  $$ export AWS_ACCESS_KEY_ID=foo AWS_SECRET_ACCESS_KEY=bar  # Optional unless deploying"
 	@echo "  $$ bob build runtimes/python-2.7.13"
 	@echo "  $$ bob deploy runtimes/python-2.7.13"
 	@echo
 	@docker run -it --rm python-buildenv-heroku-18
 tools:
 	git clone https://github.com/kennethreitz/pip-pop.git
 	mv pip-pop/bin/* vendor/pip-pop/
@@ -86,31 +86,6 @@ Each version is given a distinguishing version number. If the Library as you rec
 If the Library as you received it specifies that a proxy can decide whether future versions of the GNU Lesser General Public License shall apply, that proxy's public statement of acceptance of any version is permanent authorization for you to choose that version for the Library.
 get-pip.py license
 ------------------
 Copyright (c) 2008-2016 The pip developers (see AUTHORS.txt file)
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
 "Software"), to deal in the Software without restriction, including
 without limitation the rights to use, copy, modify, merge, publish,
 distribute, sublicense, and/or sell copies of the Software, and to
 permit persons to whom the Software is furnished to do so, subject to
 the following conditions:
 The above copyright notice and this permission notice shall be
 included in all copies or substantial portions of the Software.
 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 pip-pop license
 ---------------
@@ -134,4 +109,4 @@ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.
+THE SOFTWARE.
@@ -1,9 +0,0 @@
 [[source]]
 url = "https://pypi.python.org/simple"
 verify_ssl = true
 name = "pypi"
 [dev-packages]
 [packages]
 "bob-builder" = "==0.0.13"
@@ -1,52 +0,0 @@
 {
    "_meta": {
        "hash": {
            "sha256": "36d17c46a8b1b844b3cae475f6f42d6c0a9e59b2a9685cbcdc0985656a7a129f"
        },
        "host-environment-markers": {
            "implementation_name": "cpython",
            "implementation_version": "3.6.3",
            "os_name": "posix",
            "platform_machine": "x86_64",
            "platform_python_implementation": "CPython",
            "platform_release": "16.7.0",
            "platform_system": "Darwin",
            "platform_version": "Darwin Kernel Version 16.7.0: Thu Jun 15 17:36:27 PDT 2017; root:xnu-3789.70.16~2/RELEASE_X86_64",
            "python_full_version": "3.6.3",
            "python_version": "3.6",
            "sys_platform": "darwin"
        },
        "pipfile-spec": 6,
        "requires": {},
        "sources": [
            {
                "name": "pypi",
                "url": "https://pypi.python.org/simple",
                "verify_ssl": true
            }
        ]
    },
    "default": {
        "bob-builder": {
            "hashes": [
                "sha256:b4de49a8e436fcaf82236ea43f78413b4a4c92100726e382ab57b6bdfb38fe64",
                "sha256:288e3e765c4890fe9a63ae52ac6b4a963c13fe508482c70ff701a5ae21b9a673"
            ],
            "version": "==0.0.13"
        },
        "boto": {
            "hashes": [
                "sha256:13be844158d1bd80a94c972c806ec8381b9ea72035aa06123c5db6bc6a6f3ead",
                "sha256:deb8925b734b109679e3de65856018996338758f4b916ff4fe7bb62b6d7000d1"
            ],
            "version": "==2.48.0"
        },
        "docopt": {
            "hashes": [
                "sha256:49b3a825280bd66b3aa83585ef59c4a8c82f2c8a522dbe754a8bc8d08c85c491"
            ],
            "version": "==0.6.2"
        }
    },
    "develop": {}
 }
@@ -26,7 +26,7 @@ remote: Compressing source files... done.
 remote: Building source:
 remote:
 remote: -----> Python app detected
-remote: -----> Installing python-3.7.1
+remote: -----> Installing python-3.7.4
 remote: -----> Installing pip
 remote: -----> Installing SQLite3
 remote: -----> Installing requirements with pip
@@ -44,9 +44,10 @@ A `requirements.txt` must be present at the root of your application's repositor
 To specify your python version, you also need a `runtime.txt` file - unless you are using the default Python runtime version.
-Current default Python Runtime: Python 3.6.7
+Current default Python Runtime: Python 3.6.9
-Alternatively, you can provide a `setup.py` file, or a `Pipfile`. Using `Pipenv` will generate `runtime.txt` based on `python-version` at build time.
+Alternatively, you can provide a `setup.py` file, or a `Pipfile`.
 Using `pipenv` will generate `runtime.txt` at build time if one of the field `python_version` or `python_full_version` is specified in the `requires` section of your `Pipfile`.
 Specify a Buildpack Version
 ---------------------------
@@ -61,26 +62,32 @@ Specify a Python Runtime
 Supported runtime options include:
- `python-3.7.1`
+- `python-3.8.5`
- `python-3.6.7`
+- `python-3.7.8`
- `python-2.7.15`
+- `python-3.6.11`
 - `python-2.7.18`
 ## Tests
 The buildpack tests use [Docker](https://www.docker.com/) to simulate
 Heroku's [stack images.](https://devcenter.heroku.com/articles/stack)
-To run the test suite:
+To run the test suite against the default stack:
 ```
 make test
 ```
-Or to test in a particular stack:
+Or to test against a particular stack:
 ```
-make test-heroku-18
+make test STACK=heroku-16
-make test-heroku-16
+```
 To run only a subset of the tests:
 ```
 make test TEST_CMD=tests/versions
 ```
 The tests are run via the vendored
@@ -16,7 +16,9 @@
 set -eo pipefail
 # Boostrap the Buildpack Standard Library.
-export BPLOG_PREFIX="buildpack.python"
+# Disable unused env var warning since shellcheck doesn't know about the stdlib.
 # shellcheck disable=2034
 BPLOG_PREFIX="buildpack.python"
 export BUILDPACK_LOG_FILE=${BUILDPACK_LOG_FILE:-/dev/null}
 [ "$BUILDPACK_XTRACE" ] && set -o xtrace
@@ -42,6 +44,8 @@ export BUILD_DIR CACHE_DIR ENV_DIR
 VENDOR_URL="https://lang-python.s3.amazonaws.com/$STACK"
 if [[ -n ${BUILDPACK_VENDOR_URL:-} ]]; then
    VENDOR_URL="$BUILDPACK_VENDOR_URL"
 elif [[ -n ${USE_STAGING_BINARIES} ]]; then
    VENDOR_URL="$USE_STAGING_BINARIES/$STACK"
 fi
 export VENDOR_URL
@@ -50,27 +54,24 @@ export VENDOR_URL
 source "$BIN_DIR/default_pythons"
 # Supported Python Branches
 PY38="python-3.8"
 PY37="python-3.7"
 PY36="python-3.6"
 PY35="python-3.5"
 PY34="python-3.4"
 PY27="python-2.7"
 PYPY27="pypy2.7"
 PYPY36="pypy3.6"
 # Which stack is used (for binary downloading), if none is provided (e.g. outside of Heroku)?
 DEFAULT_PYTHON_STACK="cedar-14"
 # If pip doesn't match this version (the version we install), run the installer.
 PIP_UPDATE="9.0.2"
 export DEFAULT_PYTHON_STACK PIP_UPDATE
 export PY37 PY36 PY35 PY27 PY34
 # Common Problem Warnings:
 # This section creates a temporary file in which to stick the output of `pip install`.
 # The `warnings` subscript then greps through this for common problems and guides
 # the user towards resolution of known issues.
 WARNINGS_LOG=$(mktemp)
-export WARNINGS_LOG
+RECOMMENDED_PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
 export RECOMMENDED_PYTHON_VERSION=$DEFAULT_PYTHON_VERSION
 # The buildpack ships with a few executable tools (e.g. pip-grep, etc).
 # This installs them into the path, so we can execute them directly.
@@ -152,7 +153,7 @@ cd "$BUILD_DIR"
 # - Once the build is complete, `~/.heroku/{known-paths}` is copied back into the cache.
 # Create the cache directory, if it doesn't exist.
-mkdir -p "$CACHE_DIR"
+mkdir -p "$CACHE_DIR/.heroku"
 # Restore old artifacts from the cache.
 mkdir -p .heroku
@@ -194,8 +195,6 @@ else
  CACHED_PYTHON_STACK=$STACK
 fi
 export CACHED_PYTHON_STACK
 # Pipenv Python version support.
 # Detect the version of Python requested from a Pipfile (e.g. python_version or python_full_version).
 # Convert it to a runtime.txt file.
@@ -236,17 +235,8 @@ mtime "python.install.time" "${start}"
 # shellcheck source=bin/steps/pipenv
 source "$BIN_DIR/steps/pipenv"
 # Uninstall removed dependencies with Pip.
 # The buildpack will automatically remove any declared dependencies (in requirements.txt)
 # that were explicitly removed. This machinery is a bit complex, but it is not complicated.
 (( start=$(nowms) ))
 # shellcheck source=bin/steps/pip-uninstall
 source "$BIN_DIR/steps/pip-uninstall"
 mtime "pip.uninstall.time" "${start}"
 # If no requirements.txt file given, assume `setup.py develop` is intended.
 # This allows for people to ship a setup.py application to Heroku
 # (which is rare, but I vouch that it should work!)
 if [ ! -f requirements.txt ] && [ ! -f Pipfile ]; then
  echo "-e ." > requirements.txt
@@ -1,10 +1,16 @@
 #!/usr/bin/env bash
-DEFAULT_PYTHON_VERSION="python-3.6.8"
+# Disable unused env var warning, since shellcheck doesn't take into account
-LATEST_36="python-3.6.8"
+# that this file is sourced. We don't want to use export since it exposes
-LATEST_37="python-3.7.3"
+# the env vars to subprocesses.
-LATEST_35="python-3.5.7"
+# shellcheck disable=2034
 LATEST_34="python-3.4.10"
 LATEST_27="python-2.7.16"
-export DEFAULT_PYTHON_VERSION LATEST_37 LATEST_36 LATEST_35 LATEST_34 LATEST_27
+DEFAULT_PYTHON_VERSION="python-3.6.11"
 LATEST_38="python-3.8.5"
 LATEST_37="python-3.7.8"
 LATEST_36="python-3.6.11"
 LATEST_35="python-3.5.9"
 LATEST_34="python-3.4.10"
 LATEST_27="python-2.7.18"
 PYPY_36="pypy3.6-7.3.1"
 PYPY_27="pypy2.7-7.3.1"
@@ -0,0 +1,21 @@
 # Python Buildpack Install Steps
 TODO: Add context on Python install steps, such as why symlinking vs copying
 ## Installing Python packages using Pip
 ### Convention: Use `python` process to invoke Pip
 We don't use this convention (yet) but this is an upcoming change being considered.
 This is a bigger concern on Windows than it is in Linux environments, but an
 emerging convention in the Python community is to invoke pip using:
 ```
 python3 -m pip [options]
 ```
 Invoking pip this way ensures correct location - python knows where these
 packages are stored because it put them there (defaults to Python's pathing info).
 All normal command line options are available using this method.
@@ -22,6 +22,10 @@ source "$BIN_DIR/utils"
 if (pip-grep -s requirements.txt GDAL gdal pygdal &> /dev/null) then
  if [ ! -f ".heroku/vendor/bin/gdalserver" ]; then
    puts-warn "The vendored GDAL package in the Heroku Python Buildpack now deprecated."
    puts-warn "To enable GDAL use an alternative buildpack is available here - https://github.com/heroku/heroku-geo-buildpack"
    echo "-----> Noticed GDAL. Bootstrapping gdal."
    mkdir -p .heroku/vendor
    # Download and extract cryptography into target vendor directory.
@@ -24,6 +24,9 @@ source "$BIN_DIR/utils"
 if [[ "$BUILD_WITH_GEO_LIBRARIES" ]]; then
  mcount "buildvar.BUILD_WITH_GEO_LIBRARIES"
  puts-warn "The GDAL, GEOS and PROJ binaries and BUILD_WITH_GEO_LIBRARIES functonality are now deprecated."
  puts-warn "An alternative buildpack to enable GDAL, GEOS and PROJ use is available here - https://github.com/heroku/heroku-geo-buildpack"
  if [ ! -f ".heroku/vendor/bin/proj" ]; then
    echo "-----> Bootstrapping gdal, geos, proj."
    mkdir -p .heroku/vendor
@@ -38,9 +38,16 @@ if [ ! "$SKIP_PIP_INSTALL" ]; then
        mcount "failure.none-version"
    fi
    if grep -qi '^django==1.*' requirements.txt; then
        puts-warn "Your Django version is nearing the end of its community support."
        puts-warn "Upgrade to continue to receive security updates and for the best experience with Django."
        puts-warn "For more information, check out https://www.djangoproject.com/download/#supported-versions"
    fi
    if [ ! -f "$BUILD_DIR/.heroku/python/bin/pip" ]; then
        exit 1
    fi
    /app/.heroku/python/bin/pip install -r "$BUILD_DIR/requirements.txt" --exists-action=w --src=/app/.heroku/src --disable-pip-version-check --no-cache-dir 2>&1 | tee "$WARNINGS_LOG" | cleanup | indent
    PIP_STATUS="${PIPESTATUS[0]}"
    set -e
@@ -52,12 +59,9 @@ if [ ! "$SKIP_PIP_INSTALL" ]; then
        exit 1
    fi
    # Smart Requirements handling
    cp requirements.txt .heroku/python/requirements-declared.txt
    /app/.heroku/python/bin/pip freeze --disable-pip-version-check > .heroku/python/requirements-installed.txt
    echo
    # Install test dependencies, for CI.
    if [ "$INSTALL_TEST" ]; then
        if [[ -f "$1/requirements-test.txt" ]]; then
@@ -13,7 +13,7 @@ if [ ! "$SKIP_PIP_INSTALL" ]; then
    if ! pip-diff --stale requirements-declared.txt requirements.txt --exclude setuptools pip wheel > .heroku/python/requirements-stale.txt; then
-      mount "failure.bad-requirements"
+      mcount "failure.bad-requirements"
    fi
    rm -fr requirements-declared.txt
@@ -26,7 +26,7 @@ fi
 if [ ! "$SKIP_PIPENV_INSTALL" ]; then
-    # Pipenv support (Generate requriements.txt with pipenv).
+    # Pipenv support (Generate requirements.txt with pipenv).
    if [[ -f Pipfile ]]; then
        # Measure that we're using Pipenv.
        mcount "tool.pipenv"
@@ -60,10 +60,16 @@ if [ ! "$SKIP_PIPENV_INSTALL" ]; then
        # avoid this eager behavior.
        /app/.heroku/python/bin/pip install pipenv==$PIPENV_VERSION --upgrade --upgrade-strategy only-if-needed &> /dev/null
        # Install the test dependencies, for CI.
        if [ "$INSTALL_TEST" ]; then
            puts-step "Installing test dependencies…"
            /app/.heroku/python/bin/pipenv install --dev --system --deploy 2>&1 | cleanup | indent
        # Install the dependencies.
-        if [[ ! -f Pipfile.lock ]]; then
+        elif [[ ! -f Pipfile.lock ]]; then
            puts-step "Installing dependencies with Pipenv $PIPENV_VERSION…"
            /app/.heroku/python/bin/pipenv install --system --skip-lock 2>&1 | indent
        else
            pipenv-to-pip Pipfile.lock > requirements.txt
            "$BIN_DIR/steps/pip-uninstall"
@@ -73,12 +79,6 @@ if [ ! "$SKIP_PIPENV_INSTALL" ]; then
            puts-step "Installing dependencies with Pipenv $PIPENV_VERSION…"
            /app/.heroku/python/bin/pipenv install --system --deploy 2>&1 | indent
        fi
        # Install the test dependencies, for CI.
        if [ "$INSTALL_TEST" ]; then
            puts-step "Installing test dependencies…"
            /app/.heroku/python/bin/pipenv install --dev --system --deploy 2>&1 | cleanup | indent
        fi
    fi
 else
    export SKIP_PIP_INSTALL=1
@@ -27,6 +27,9 @@ if [[ -f $BUILD_DIR/Pipfile ]]; then
                if [ "$PYTHON" = 3.7 ]; then
                    echo "$LATEST_37" > "$BUILD_DIR/runtime.txt"
                fi
                if [ "$PYTHON" = 3.8 ]; then
                    echo "$LATEST_38" > "$BUILD_DIR/runtime.txt"
                fi
            fi
@@ -9,8 +9,19 @@ VENDORED_PYTHON="${VENDOR_URL}/runtimes/$PYTHON_VERSION.tar.gz"
 SECURITY_UPDATE="Python has released a security update! Please consider upgrading to"
 ONLY_SUPPORTED_2_VERSION="Only the latest version of Python 2 is supported on the platform. Please consider upgrading to"
 PYTHON_2_EOL_UPDATE="Python 2 has reached it's community EOL. Upgrade your Python runtime to maintain a secure application as soon as possible."
 # check if runtime exists
 if curl --output /dev/null --silent --head --fail "$VENDORED_PYTHON"; then
  if [[ "$PYTHON_VERSION" == $PY38* ]]; then
    # do things to alert the user of security release available
    if [ "$PYTHON_VERSION" != "$LATEST_38" ]; then
      puts-warn "$SECURITY_UPDATE" "$LATEST_38"
      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
    fi
  fi
  if [[ "$PYTHON_VERSION" == $PY37* ]]; then
    # do things to alert the user of security release available
    if [ "$PYTHON_VERSION" != "$LATEST_37" ]; then
@@ -41,8 +52,26 @@ if curl --output /dev/null --silent --head --fail "$VENDORED_PYTHON"; then
  fi
  if [[ "$PYTHON_VERSION" == $PY27* ]]; then
    # security update note
    if [[ "$(date "+%Y")" -gt "2019" ]]; then
      puts-warn "$PYTHON_2_EOL_UPDATE"
      echo "       Learn More: https://devcenter.heroku.com/articles/python-2-7-eol-faq"
    fi
    if [ "$PYTHON_VERSION" != "$LATEST_27" ]; then
-      puts-warn "$SECURITY_UPDATE" "$LATEST_27"
+      puts-warn "$ONLY_SUPPORTED_2_VERSION" "$LATEST_27"
      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
    fi
  fi
  if [[ "$PYTHON_VERSION" == $PYPY27* ]]; then
    # security update note
    if [ "$PYTHON_VERSION" != "$PYPY_27" ]; then
      puts-warn "Could not find that Pypy version. Did you mean" "${PYPY_27}?"
      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
    fi
  fi
  if [[ "$PYTHON_VERSION" == $PYPY36* ]]; then
    # security update note
    if [ "$PYTHON_VERSION" != "$PYPY_36" ]; then
      puts-warn "Could not find that Pypy version. Did you mean" "${PYPY_36}?"
      echo "       Learn More: https://devcenter.heroku.com/articles/python-runtimes"
    fi
  fi
@@ -57,14 +86,6 @@ if [[ "$STACK" != "$CACHED_PYTHON_STACK" ]]; then
    rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor .heroku/python .heroku/python-sqlite3-version
 fi
 # need to clear the cache for first time installing SQLite3,
 # since the version is changing and could lead to runtime errors
 # with compiled extensions.
 if [ -d .heroku/python ] && [ ! -f .heroku/python-sqlite3-version ] && python_sqlite3_check "$PYTHON_VERSION"; then
  puts-step "Need to update SQLite3, clearing cache"
  rm -fr .heroku/python-stack .heroku/python-version .heroku/python .heroku/vendor
 fi
 if [ -f .heroku/python-version ]; then
  if [ ! "$(cat .heroku/python-version)" = "$PYTHON_VERSION" ]; then
      puts-step "Found $(cat .heroku/python-version), removing"
@@ -74,6 +95,24 @@ if [ -f .heroku/python-version ]; then
  fi
 fi
 # Check if we should reinstall python dependencies
 if [[ ! -f "$CACHE_DIR/.heroku/requirements.txt" ]]; then
  # IF there's no cached dependencies, update cached version of requirements.txt
  # This should only run for new apps and first deploys after this update
  cp -R "$BUILD_DIR/requirements.txt" "$CACHE_DIR/.heroku/requirements.txt"
 else
  # IF there IS a cached directory, check for differences with the new one
  if ! diff "$BUILD_DIR/requirements.txt" "$CACHE_DIR/.heroku/requirements.txt" &> /dev/null; then
    puts-step "Requirements file has been changed, clearing cached dependencies"
    # if there are any differences, clear the Python cache
    # Installing Python over again does not take noticably more time
    cp -R "$BUILD_DIR/requirements.txt" "$CACHE_DIR/.heroku/requirements.txt"
    rm -rf .heroku/python
    unset SKIP_INSTALL
  else
    puts-step "No change in requirements detected, installing from cache"
  fi
 fi
 if [ ! "$SKIP_INSTALL" ]; then
    puts-step "Installing $PYTHON_VERSION"
@@ -92,24 +131,52 @@ if [ ! "$SKIP_INSTALL" ]; then
  # Record for future reference.
  echo "$PYTHON_VERSION" > .heroku/python-version
  echo "$STACK" > .heroku/python-stack
  FRESH_PYTHON=true
  hash -r
 fi
 set -e
-# If Pip isn't up to date:
+PIP_VERSION='20.0.2'
-if [ "$FRESH_PYTHON" ] || [[ ! $(pip --version) == *$PIP_UPDATE* ]]; then
+SETUPTOOLS_VERSION='39.0.1'
 WHEEL_VERSION='0.34.2'
-  puts-step "Installing pip"
+if [[ "${PYTHON_VERSION}" == ${PY34}* ]]; then
-
+  # Python 3.4 support was dropped in pip 19.2+ and wheel 0.34.0+.
-  # Remove old installations.
+  PIP_VERSION='19.1.1'
-  rm -fr /app/.heroku/python/lib/python*/site-packages/pip-*
+  WHEEL_VERSION='0.33.6'
  rm -fr /app/.heroku/python/lib/python*/site-packages/setuptools-*
  /app/.heroku/python/bin/python "$ROOT_DIR/vendor/get-pip.py" pip=="$PIP_UPDATE" &> /dev/null
  /app/.heroku/python/bin/pip install "$ROOT_DIR/vendor/setuptools-39.0.1-py2.py3-none-any.whl" &> /dev/null
 fi
-set -e
+# We don't use get-pip.py, since:
 #  - it uses `--force-reinstall`, which is unnecessary here and slows down repeat builds
 #  - it means downloading pip twice (once embedded in get-pip.py, and again during
 #    the install, since get-pip.py can't install the embedded version directly)
 #  - we would still have to manage several versions of get-pip.py, to support older Pythons.
 # Instead, we use the pip wheel to install itself, using the method described here:
 # https://github.com/pypa/pip/issues/2351#issuecomment-69994524
 PIP_WHEEL_FILENAME="pip-${PIP_VERSION}-py2.py3-none-any.whl"
 PIP_WHEEL_URL="https://lang-python.s3.amazonaws.com/common/${PIP_WHEEL_FILENAME}"
 PIP_WHEEL="${TMPDIR:-/tmp}/${PIP_WHEEL_FILENAME}"
 if ! curl -sSf "${PIP_WHEEL_URL}" -o "$PIP_WHEEL"; then
  mcount "failure.python.download-pip"
  puts-warn "Failed to download pip"
  exit 1
 fi
 if [[ -f "$BUILD_DIR/Pipfile" ]]; then
  # The buildpack is pinned to old pipenv, which requires older pip.
  # Pip 9.0.2 doesn't support installing itself from a wheel, so we have to use split
  # versions here (ie: installer pip version different from target pip version).
  PIP_VERSION='9.0.2'
  PIP_TO_INSTALL="pip==${PIP_VERSION}"
 else
  PIP_TO_INSTALL="${PIP_WHEEL}"
 fi
 puts-step "Installing pip ${PIP_VERSION}, setuptools ${SETUPTOOLS_VERSION} and wheel ${WHEEL_VERSION}"
 /app/.heroku/python/bin/python "${PIP_WHEEL}/pip" install --quiet --disable-pip-version-check --no-cache \
  "${PIP_TO_INSTALL}" "setuptools==${SETUPTOOLS_VERSION}" "wheel==${WHEEL_VERSION}"
 hash -r
@@ -3,19 +3,8 @@
 # shellcheck source=bin/utils
 source "$BIN_DIR/utils"
 sqlite3_version() {
  if [ "$STACK" = "cedar-14" ]; then
    SQLITE3_VERSION="3.8.2-1ubuntu2.2"
  else
    SQLITE3_VERSION=${SQLITE3_VERSION:-$(dpkg -s libsqlite3-0 | grep Version | sed 's/Version: //')}
  fi
  export SQLITE3_VERSION
 }
 sqlite3_install() {
  HEROKU_PYTHON_DIR="$1"
  SQLITE3_VERSION="$2"
  HEADERS_ONLY="$3"
  mkdir -p "$HEROKU_PYTHON_DIR"
@@ -33,9 +22,9 @@ sqlite3_install() {
  apt-get $APT_OPTIONS update > /dev/null 2>&1
  if [ -z "$HEADERS_ONLY" ]; then
-    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev="$SQLITE3_VERSION" sqlite3="$SQLITE3_VERSION" > /dev/null 2>&1
+    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev sqlite3 > /dev/null 2>&1
  else
-    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev="$SQLITE3_VERSION"
+    apt-get $APT_OPTIONS -y -d --reinstall install libsqlite3-dev
  fi
  find "$APT_CACHE_DIR/archives/" -name "*.deb" -exec dpkg -x {} "$HEROKU_PYTHON_DIR/sqlite3/" \;
@@ -68,7 +57,6 @@ sqlite3_install() {
 }
 buildpack_sqlite3_install() {
  sqlite3_version
  HEROKU_PYTHON_DIR="$BUILD_DIR/.heroku/python"
  SQLITE3_VERSION_FILE="$BUILD_DIR/.heroku/python-sqlite3-version"
@@ -76,16 +64,14 @@ buildpack_sqlite3_install() {
    INSTALLED_SQLITE3_VERSION=$(cat "$SQLITE3_VERSION_FILE")
  fi
-  # python version check
+  puts-step "Installing SQLite3"
  if python_sqlite3_check "$PYTHON_VERSION"; then
    # only install if the sqlite3 version has changed
    if [ "$INSTALLED_SQLITE3_VERSION" != "$SQLITE3_VERSION" ]; then
      puts-step "Installing SQLite3"
      sqlite3_install "$BUILD_DIR/.heroku/python" "$SQLITE3_VERSION"
-      # save version installed
+  if sqlite3_install "$BUILD_DIR/.heroku/python" ; then
-      mkdir -p "$CACHE_DIR/.heroku/"
+    mcount "success.python.sqlite3"
-      echo "$SQLITE3_VERSION" > "$CACHE_DIR/.heroku/python-sqlite3-version"
+  else
-    fi
+    echo "Sqlite3 failed to install."
    mcount "failure.python.sqlite3"
  fi
  mkdir -p "$CACHE_DIR/.heroku/"
 }
@@ -1,41 +1,57 @@
 # Python Buildpack Binaries
-For Cedar-14 stack
+## Building the Docker Images
 ------------------
-To get started with it, create an app on Heroku inside a clone of this repository, and set your S3 config vars:
+**After every change to your formulae, perform the following** from the root of the Git repository (not from `builds/`) to rebuild the images for each stack:
-    $ heroku create --buildpack https://github.com/heroku/heroku-buildpack-python#not-heroku
+    $ docker build --pull --tag heroku-python-build-cedar-14 --file $(pwd)/builds/cedar-14.Dockerfile .
-    $ heroku config:set WORKSPACE_DIR=builds
+    $ docker build --pull --tag heroku-python-build-heroku-16 --file $(pwd)/builds/heroku-16.Dockerfile .
-    $ heroku config:set AWS_ACCESS_KEY_ID=<your_aws_key>
+    $ docker build --pull --tag heroku-python-build-heroku-18 --file $(pwd)/builds/heroku-18.Dockerfile .
    $ heroku config:set AWS_SECRET_ACCESS_KEY=<your_aws_secret>
    $ heroku config:set S3_BUCKET=<your_s3_bucket_name>
 ## Using the Image
-Then, shell into an instance and run a build by giving the name of the formula inside `builds`:
+You can e.g. `bash` into each of the images you built using their tag:
-    $ heroku run bash
+    docker run --rm -ti heroku-python-build-cedar-14 bash
-    Running `bash` attached to terminal... up, run.6880
+    docker run --rm -ti heroku-python-build-heroku-16 bash
-    ~ $ bob build runtimes/python-2.7.6
+    docker run --rm -ti heroku-python-build-heroku-18 bash
-    Fetching dependencies... found 2:
+You then have a shell where you can run `bob build`, `bob deploy`, and so forth. You can of course also invoke these programs directly with `docker run`:
      - libraries/sqlite
-    Building formula runtimes/python-2.7.6:
+    docker run --rm -ti heroku-python-build-heroku-18 bob build runtimes/python-2.7.15
        === Building Python 2.7.6
        Fetching Python v2.7.6 source...
        Compiling...
-If this works, run `bob deploy` instead of `bob build` to have the result uploaded to S3 for you.
+In order to `bob deploy`, AWS credentials must be set up, as well as name and prefix of your custom S3 bucket (unless you're deploying to the Heroku production buckets that are pre-defined in each `Dockerfile`); see next section for details.
-To speed things up drastically, it'll usually be a good idea to `heroku run bash --size PX` instead.
+## Configuration
-For Heroku-16 stack
+File `dockerenv.default` contains a list of required env vars; most of these have default values defined in `Dockerfile`. You can copy this file to a location outside the buildpack and modify it with the values you desire and pass its location with `--env-file`, or pass the env vars to `docker run` using `--env`.
 -------------------
-1. Ensure GNU Make and Docker are installed.
+Out of the box, each `Dockerfile` has the correct values predefined for `S3_BUCKET`, `S3_PREFIX`, and `S3_REGION`. If you're building your own packages, you'll likely want to change `S3_BUCKET` and `S3_PREFIX` to match your info. Instead of setting `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` into that file, you may also pass them to `docker run` through the environment, or explicitly using `--env`, in order to prevent accidental commits of credentials.
 2. From the root of the buildpack repository, run: `make buildenv-heroku-16`
 3. Follow the instructions displayed!
 ### Passing AWS credentials to the container
-Enjoy :)
+If you want to deploy packages and thus need to pass `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`, you can either pass them explicitly, through your environment, or through an env file.
 #### Passing credentials explicitly
    docker run --rm -ti -e AWS_ACCESS_KEY_ID=... -e AWS_SECRET_ACCESS_KEY=... heroku-python-build-heroku-18 bash
 #### Passing credentials through  the environment
 The two environment variables `AWS_ACCESS_KEY_ID`and `AWS_SECRET_ACCESS_KEY` are defined in `builds/dockerenv.default`, without values. This will cause Docker to "forward" values for these variables from the current environment, so you can pass them in:
    AWS_ACCESS_KEY_ID=... AWS_SECRET_ACCESS_KEY=... docker run --rm -ti --env-file=builds/dockerenv.default heroku-python-build-heroku-18 bash
 or
    export AWS_ACCESS_KEY_ID=...
    export AWS_SECRET_ACCESS_KEY=...
    docker run --rm -ti --env-file=builds/dockerenv.default heroku-python-build-heroku-18 bash
 #### Passing credentials through a separate env file
 This method is the easiest for users who want to build packages in their own S3 bucket, as they will have to adjust the `S3_BUCKET` and `S3_PREFIX` environment variable values anyway from their default values.
 For this method, it is important to keep the credentials file in a location outside the buildpack, so that your credentials aren't accidentally committed. Copy `builds/dockerenv.default` **to a safe location outside the buildpack directory**, and insert your values for `AWS_ACCESS_KEY_ID`and `AWS_SECRET_ACCESS_KEY`.
    docker run --rm -ti --env-file=../SOMEPATHOUTSIDE/s3.env heroku-python-build-heroku-18 bash
@@ -0,0 +1,15 @@
 FROM heroku/cedar:14
 WORKDIR /app
 ENV WORKSPACE_DIR="/app/builds" \
    S3_BUCKET="lang-python" \
    S3_PREFIX="cedar-14/" \
    DEBIAN_FRONTEND=noninteractive \
    STACK="cedar-14"
 RUN apt-get update && apt-get install -y python-pip libsqlite3-dev realpath && rm -rf /var/lib/apt/lists/*
 COPY requirements.txt /app/
 RUN pip install -r /app/requirements.txt
 COPY . /app
@@ -0,0 +1,5 @@
 AWS_ACCESS_KEY_ID
 AWS_SECRET_ACCESS_KEY
 S3_BUCKET
 S3_PREFIX
 S3_REGION
@@ -3,9 +3,11 @@ FROM heroku/heroku:16-build
 WORKDIR /app
 ENV WORKSPACE_DIR="/app/builds" \
    S3_BUCKET="lang-python" \
-    S3_PREFIX="heroku-16/"
+    S3_PREFIX="heroku-16/" \
    DEBIAN_FRONTEND=noninteractive \
    STACK="heroku-16"
-RUN apt-get update && apt-get install -y python-pip && rm -rf /var/lib/apt/lists/*
+RUN apt-get update && apt-get install -y python-pip libsqlite3-dev && rm -rf /var/lib/apt/lists/*
 COPY requirements.txt /app/
 RUN pip install --disable-pip-version-check --no-cache-dir -r /app/requirements.txt
@@ -0,0 +1,15 @@
 FROM heroku/heroku:18-build
 WORKDIR /app
 ENV WORKSPACE_DIR="/app/builds" \
    S3_BUCKET="lang-python" \
    S3_PREFIX="heroku-18/" \
    DEBIAN_FRONTEND=noninteractive \
    STACK="heroku-18"
 RUN apt-get update && apt-get install --no-install-recommends -y python-pip-whl=9.0.1-2 python-pip=9.0.1-2 python-setuptools python-wheel libsqlite3-dev && rm -rf /var/lib/apt/lists/*
 COPY requirements.txt /app/
 RUN pip install --disable-pip-version-check --no-cache-dir -r /app/requirements.txt
 COPY . /app
@@ -1,28 +0,0 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/vendor/
 OUT_PREFIX=$1
 # Skip the build for heroku-16.
 if [[ $S3_PREFIX == "heroku-16" ]]; then
    exit 0
 fi
 # Use new path, containing autoconf.
 export PATH="/app/.heroku/python/bin/:$PATH"
 hash -r
 echo "Building libffi…"
 SOURCE_TARBALL='ftp://sourceware.org/pub/libffi/libffi-3.1.tar.gz'
 curl -L $SOURCE_TARBALL | tar x
 cd libffi-3.1
 ./configure --prefix=$OUT_PREFIX --disable-static &&
 make
 make install
 # Cleanup
 cd ..
@@ -3,9 +3,9 @@
 OUT_PREFIX=$1
-# Skip the build for heroku-16.
+if [[ $S3_PREFIX != "cedar-14" ]]; then
-if [[ $S3_PREFIX == "heroku-16" ]]; then
+    echo "libmemcached only needs to be built for cedar-14, since newer stacks include it in the base image"
-    exit 0
+    exit 1
 fi
 # fail hard
@@ -0,0 +1,22 @@
 #!/usr/bin/env bash
 # fail hard
 set -o pipefail
 # fail harder
 set -eu
 OUT_PREFIX=$1
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 dep_name=$(basename $BASH_SOURCE) # this is us
 dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
 dep_package=${dep_name}2-v${dep_version} # it's always "pypy2-…"
 dep_dirname=${dep_package}-linux64
 dep_archive_name=${dep_dirname}.tar.bz2
 dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
 echo "Building PyPy…"
 curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
 ln "$OUT_PREFIX/bin/pypy" "$OUT_PREFIX/bin/python"
@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+source $(dirname $0)/pypy
 OUT_PREFIX=$1
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.3.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.3.1-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+source $(dirname $0)/pypy
 OUT_PREFIX=$1
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.6.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.6.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 and heroku-16 stacks, not cedar.
+source $(dirname $0)/pypy
 OUT_PREFIX=$1
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.7.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.7.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+source $(dirname $0)/pypy
 OUT_PREFIX=$1
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.7.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.7.1-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -2,11 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/pypy
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy2-v5.8.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy2-v5.8.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy $OUT_PREFIX/bin/python
@@ -0,0 +1,23 @@
 #!/usr/bin/env bash
 # fail hard
 set -o pipefail
 # fail harder
 set -eu
 OUT_PREFIX=$1
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 dep_name=$(basename $BASH_SOURCE) # this is us
 dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
 dep_package=${dep_name}-v${dep_version} # it's always "pypy2-…"
 dep_dirname=${dep_package}-linux64
 dep_archive_name=${dep_dirname}.tar.bz2
 dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
 echo "Building PyPy…"
 echo "${dep_url}"
 curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
 ln "$OUT_PREFIX/bin/pypy" "$OUT_PREFIX/bin/python"
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/pypy2.7
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/pypy2.7
@@ -0,0 +1,22 @@
 #!/usr/bin/env bash
 # fail hard
 set -o pipefail
 # fail harder
 set -eu
 OUT_PREFIX=$1
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 dep_name=$(basename $BASH_SOURCE) # this is us
 dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
 dep_package=${dep_name}${dep_version_prefix:-}-v${dep_version}${dep_version_suffix:-}
 dep_dirname=${dep_package}-linux64
 dep_archive_name=${dep_dirname}.tar.bz2
 dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
 echo "Building PyPy3…"
 curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
 ln "$OUT_PREFIX/bin/pypy3" "$OUT_PREFIX/bin/python"
@@ -2,13 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+source $(dirname $0)/pypy3
 OUT_PREFIX=$1
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-2.4.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-2.4.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python
@@ -2,13 +2,7 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-# NOTICE: This formula only works for the cedar-14 stack, not cedar.
+# version pypy3-5.5.0 is really called pypy3.3-v5.5.0-alpha
-
+dep_version_prefix=".3"
-OUT_PREFIX=$1
+dep_version_suffix="-alpha"
-
+source $(dirname $0)/pypy3
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3.3-v5.5.0-alpha-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.5.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python
@@ -2,11 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/pypy3
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-v5.7.1-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.7.1-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python
@@ -2,11 +2,4 @@
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/pypy3
 echo "Building PyPy…"
 SOURCE_TARBALL='https://bitbucket.org/pypy/pypy/downloads/pypy3-v5.8.0-linux64.tar.bz2'
 curl -L $SOURCE_TARBALL | tar jx
 cp -R pypy3-v5.8.0-linux64/* $OUT_PREFIX
 ln $OUT_PREFIX/bin/pypy3 $OUT_PREFIX/bin/python
@@ -0,0 +1,23 @@
 #!/usr/bin/env bash
 # fail hard
 set -o pipefail
 # fail harder
 set -eu
 OUT_PREFIX=$1
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 dep_name=$(basename $BASH_SOURCE) # this is us
 dep_version=${dep_formula##*"/${dep_name}-"} # "subtract" our name from full version name
 dep_package=${dep_name}${dep_version_prefix:-}-v${dep_version}${dep_version_suffix:-}
 dep_dirname=${dep_package}-linux64
 dep_archive_name=${dep_dirname}.tar.bz2
 dep_url=https://bitbucket.org/pypy/pypy/downloads/${dep_archive_name}
 echo "Building PyPy3…"
 echo "${dep_url}"
 curl -L "${dep_url}" | tar jx -C "${OUT_PREFIX}" --strip-components 1 # extract to $OUT_PREFIX, drop the first directory level, which is the archive name
 ln "$OUT_PREFIX/bin/pypy3" "$OUT_PREFIX/bin/python"
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/pypy3.6
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/pypy3.6
@@ -1,15 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.10/Python-2.7.10.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.10 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --with-ensurepip=no
 make
 make install
@@ -1,15 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.11/Python-2.7.11.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.11 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --with-ensurepip=no
 make
 make install
@@ -1,15 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.12/Python-2.7.12.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.12 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --with-ensurepip=no
 make
 make install
@@ -1,19 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.13/Python-2.7.13.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.13 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -1,19 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.14/Python-2.7.14.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.14 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -1,27 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.15/Python-2.7.15.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.15 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -1,27 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.16/Python-2.7.16.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.16 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -0,0 +1,27 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 OUT_PREFIX=$1
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.17/Python-2.7.17.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.17 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -0,0 +1,27 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 OUT_PREFIX=$1
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.18/Python-2.7.18.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.18 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
@@ -1,15 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python2
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/2.7.9/Python-2.7.9.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-2.7.9 src
 cd src
 ./configure --prefix=$OUT_PREFIX  --with-ensurepip=no
 make
 make install
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -1,18 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
 OUT_PREFIX=$1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.5.2/Python-3.5.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.5.2 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
 source $(dirname $0)/python3
@@ -1,18 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
 OUT_PREFIX=$1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.5.3/Python-3.5.3.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.5.3 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.5.6/Python-3.5.6.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.5.6 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.7.2/Python-3.7.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.7.2 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -1,18 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
 OUT_PREFIX=$1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.0/Python-3.6.0.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.0 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
 source $(dirname $0)/python3
@@ -1,18 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
 OUT_PREFIX=$1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.1/Python-3.6.1.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.1 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -1,21 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.2/Python-3.6.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.2 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,21 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.3/Python-3.6.3.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.3 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,21 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.4/Python-3.6.4.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.4 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,21 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 # Build Deps: libraries/sqlite
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.5/Python-3.6.5.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.5 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,29 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.6/Python-3.6.6.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.6 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.7/Python-3.6.7.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.7 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.6.8/Python-3.6.8.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.6.8 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -1,29 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.7.0/Python-3.7.0.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.7.0 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 ln $OUT_PREFIX/bin/python3 $OUT_PREFIX/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.7.1/Python-3.7.1.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.7.1 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.7.2/Python-3.7.2.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.7.2 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -1,32 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
-OUT_PREFIX=$1
+source $(dirname $0)/python3
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # shellcheck source=bin/utils
 source "$BIN_DIR/steps/sqlite3"
 sqlite3_version
 echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
 sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
 echo "Building Python…"
 SOURCE_TARBALL='https://python.org/ftp/python/3.7.3/Python-3.7.3.tgz'
 curl -L $SOURCE_TARBALL | tar xz
 mv Python-3.7.3 src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,4 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 source $(dirname $0)/python3
@@ -0,0 +1,33 @@
 #!/usr/bin/env bash
 # Build Path: /app/.heroku/python/
 OUT_PREFIX=$1
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # Orient ourselves and build download link
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 BASE=${dep_formula##*/} # this gives us relative path
 python_version=${BASE^} # this gives us only the filename with version number
 version_number=$(echo "$python_version" | cut -d- -f2) # this returns just X.X.X
 dep_url=https://python.org/ftp/python/${version_number}/${python_version}.tgz
 echo "Building ${python_version}..."
 echo "Pulling from source: ${dep_url}"
 curl -L "${dep_url}" | tar xz -C "${OUT_PREFIX}"
 mv "${OUT_PREFIX}/${python_version}" src
 cd src
 ./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Create links to SQLITE headers so Python can call them at runtime
 mkdir -p ${OUT_PREFIX}/include ${OUT_PREFIX}/lib/x86_64-linux-gnu
 cp /usr/include/sqlite3*.h ${OUT_PREFIX}/include
 ln -fs $(realpath /usr/lib/x86_64-linux-gnu/libsqlite3.so) ${OUT_PREFIX}/lib/x86_64-linux-gnu/libsqlite3.so
@@ -0,0 +1,37 @@
 #!/usr/bin/env bash
 # fail hard
 set -o pipefail
 # fail harder
 set -eu
 OUT_PREFIX=$1
 BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
 export BIN_DIR
 # Orient ourselves and build download link
 dep_formula=${0#$WORKSPACE_DIR/} # this is the original script, e.g. pypy-5.3.1
 BASE=${dep_formula##*/} # this gives us relative path
 python_version=${BASE^} # this gives us only the filename with version number
 version_number=$(echo "$python_version" | cut -d- -f2) # this returns just X.X.X
 dep_url=https://python.org/ftp/python/${version_number}/${python_version}.tgz
 echo "Building Python 3..."
 echo "Pulling from source: ${dep_url}"
 curl -L "${dep_url}" | tar xz -C "${OUT_PREFIX}"
 mv "${OUT_PREFIX}/${python_version}" src
 cd src
 ./configure --prefix=$OUT_PREFIX --with-ensurepip=no
 make
 make install
 # Remove unneeded test directories, similar to the official Docker Python images:
 # https://github.com/docker-library/python
 find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
 # Remove spare /
 LOCATION=${OUT_PREFIX%?}
 ln $LOCATION/bin/python3 $LOCATION/bin/python
@@ -1,5 +1,6 @@
 {
  "python": [
-    "heroku/python-getting-started"
+    "heroku/python-getting-started",
    "sharpstone/python_default"
  ]
 }
@@ -1,3 +1,5 @@
 ---
 - - "./repos/python/python-getting-started"
-  - f56b90499ec11e1c9576da2f8c7331300e189db3
+  - master
 - - "./repos/python/python_default"
  - ca947f69027b2a30be5d26f9a42f25e54f4d7a1a
@@ -1,3 +1,3 @@
 docopt==0.6.2
-bob-builder
+bob-builder==0.0.17
 boto==2.48.0
--- a/Show More
+++ b/Show More